feat(sim): GPS/Sensors home pages + repeater instant self-advert

- Turn on ENV_INCLUDE_GPS/UI_SENSORS_PAGE for the sim build (both were
  compiled out entirely, so the GPS and Sensors home-page carousel
  entries didn't exist regardless of home_pages_mask) -- SimSensorManager
  already fed a real JS-settable GPS fix and a temperature/battery
  channel with nothing to display them.
- Add sim_test_advert_flood() to the repeater build too, mirroring
  companion_radio's hook: MyMesh::updateAdvertTimer() otherwise leaves
  the repeater's first self-advert 2 minutes out, so a host page
  couldn't make it discoverable as a contact (needed for admin login)
  right away.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018iubftDmKNWmkNnhJRz8UH

variants/sim/build_wasm.sh

@@ -136,6 +136,17 @@ DEFINES=(
   -DFIRMWARE_SOLO_BUILD=1
   -DMAX_CONTACTS=100
   -DMAX_GROUP_CHANNELS=8
+  # Both off by default on every real board variant except the GPS/sensor-
+  # carrying ones (see variants/wio-tracker-l1/platformio.ini,
+  # variants/heltec_t114/platformio.ini etc.) -- without ENV_INCLUDE_GPS,
+  # HomeScreen's GPS enum entry (ui-new/UITask.cpp) doesn't even exist in
+  # the build, so the "GPS" home page from sim_test_show_all_home_pages'
+  # mask=0 has nothing to map to. The demo site wants both on: SimSensorManager
+  # already feeds a real (JS-settable) GPS fix and one temperature/battery
+  # channel (see SimSensorManager.h) -- these two flags are what actually
+  # surface them as on-device pages.
+  -DENV_INCLUDE_GPS=1
+  -DUI_SENSORS_PAGE=1
 )
 
 # -funsigned-char: carried over from Phase 1 verbatim -- real ARM cores